Melanoma skin cancer can be fatal unless caught early, but most skin lesions are harmless. Dermoscopy with training can help with diagnosis. This blog is not a substitute for a medical opinion-if you are worried about a changing or funny looking mole or spot, get it checked by a doctor with suitable skills.

Dark changing lesion on elderly white face

This lesion is suspicious from the history of change in size and colour. Also it is on an older white person’s face so must be suspicious on an ‘offender profile’ basis. Although we are seeing more skin cancers in the young, the vast majority still occur in older white people, and the face is the most sun exposed area for most people. Many such lesions will be benign, particularly seborrhoiec keratoses. The dermoscope can very often positively identify such lesions allowing reassurance. Let’s have a closer look at this one.

There are three colours and one of them is red-not good. The upper portion is a medium/dark brown with numerous small round holes of equall size. Study these carefully, they are adnexal gland openings, most likely sweat ducts. When pigment on the face flows around these it creates a ‘pseudonetwork’. Pseudonetwork can be benign or malignant, it all depends on colour, regularity and whether or not the gland openings (little circles) are preserved. This section is not particularly worrying, although far from perfectly regular. The bottom right hand part of this section is darker. However, look further down.

Can you see any of the little cirlces in the red portion? I can’t. This suggests there is something wrong. Growing malignant cells will destroy normal structures such as sweat gland openings and hair shafts. Can we see any features allowing a positive diagnosis of a seborrhoiec keratosis or other benign lesion? I can’t. There is a little bit of keratin, but not enough to characterise this as a ‘keratinising’ lesion.

The decision was to biopsy. This was a lentigo maligna developing into melanoma,leading to full excision.

Facial lesions can be challenging. The key lessons in this case are that in view of the history, it was necessary to EITHER make a confident diagnosis of benignity on positive grounds OR get tissue for histopathological diagnosis. The first option was not possible, leading to the latter option.